NetNewsLedger Weather Desk | Monday, June 23, 2025 – Toronto Weather Update
Toronto Sizzles Under Blazing Heat and Humidity — Heat Warning Remains in Effect
Toronto is in the throes of a serious summer heat event as the city continues to roast under dangerously high temperatures and sweltering humidity. With a Heat Warning still in effect, Environment Canada urges residents to take precautions and stay cool and hydrated through at least Tuesday night.
Monday’s Weather – Heat Builds to a Boiling Point
As of 6:00 AM EDT, conditions at Toronto Pearson International Airport are already toasty at 23.1°C, with a humidex of 31. Humidity is running high at 84%, making even the morning air feel muggy. Winds are light from the southeast at 6 km/h, and pressure sits at 101.8 kPa and rising. Visibility is excellent at 24 km, and skies are mainly sunny—though for many, that’s more warning than promise.
By this afternoon, temperatures are forecast to soar to 36°C, with a humidex of 46—a level considered dangerously high. The UV index is 10, rated very high, so even brief sun exposure requires protection. Winds will pick up slightly from the southwest at 20 km/h late in the day, but they’ll offer little relief from the heat dome hanging over southern Ontario.
Tonight Through Midweek – The Heat Holds On
Tonight will offer little respite, with an overnight low of 25°C, maintaining that stifling overnight heat and putting extra strain on vulnerable populations.
Tuesday is set to continue the swelter with a high of 33°C and humidex nearing 42. Expect sunny skies to give way to increasing cloudiness, with a 30% chance of afternoon showers and risk of a thunderstorm. Winds will be a meteorological juggling act—starting west at 20 km/h gusting to 40, then shifting north in the afternoon at similar strength.
Tuesday night brings cloudy periods with a 30% chance of showers and a low of 21°C. Wednesday follows with a high near 28°C and continued risk of showers, keeping things steamy through midweek.
Heat Safety Tips & Wardrobe Advice
When stepping outside, opt for lightweight, light-coloured, and loose-fitting clothing, and don’t forget your wide-brimmed hat and sunscreen. Keep hydrated—drink water frequently, even before you feel thirsty. Avoid strenuous outdoor activities during peak heat hours, and check in on elderly family members, neighbours, and anyone who may be vulnerable.
Also, let’s be blunt: never leave kids or pets in vehicles, even briefly. It can be deadly in just minutes.
Did You Know?
Toronto’s all-time highest recorded temperature is 40.6°C, set back on July 7, 1936—in the midst of another infamous Ontario heatwave. We’re not quite there today, but with humidex readings reaching into the mid-40s, it’ll feel just as intense.
